Natural latex rubber is coagulated elastic latex, obtained from the white, milky liquid known as latex that circulates through small veins in the inner bark of certain trees (rubber trees) native to tropical and semitropical regions of the world. Since the early 20th century the chief source of latex has been the Heveabrasiliensis (Euphorbiaceae family) tree. It is a tall tree of softwood with high, branching limbs and a large area of bark. The rubber trees are planted in rows on rubber plantations that cover vast tracts of land in Southeast Asia. The Heveabrasiliensis tree is indigenous to South America but was adapted by English botanists for Africa, India and Southeast Asia during the 19th century. Although other varieties of rubber trees have been cultivated, the Heveabrasiliensis is now responsible for all of the commercial natural rubber production in the world.
The Heveabrasiliensistree produces latex, which is secreted from cuts, or a tap located on the tree, as a milky sap. Special cells of the rubber plant called laticifers produce latex. In general, the latex has a biological function in herbivore defense. These laticifers act as a reservoir for biosynthetic materials and metabolic by-products. All latexes are emulsions, aqueous suspensions of insoluble materials, which include alkaloids, terpenes, resins, phenolics, proteins, sugars, and long-chain hydrocarbons.
Harvesting the latex is accomplished when the bark of the Heveabrasiliensis tree is partially cut through (tapped) with a knife. This causes the latex to be secreted from the cut and dries to yield a rubbery film. The latex consists of an aqueous suspension of small particles, about 0.5 micrometer in diameter, of cis-polyisoprene, a linear rubbery polymer of high molecular weight. The rubber content of the suspension is about 30 percent.
Rubber trees are tapped about once every two days, yielding a cupful of latex, containing approximately 15 grams of solid rubber, daily. The standard method of tapping is to score the tree with a knife for half the circumference of the trunk, slanting the cut down from left to right at an angle of 30 degrees starting at the highest point convenient to the tapper. Each subsequent cut is made immediately below its predecessor. Trees are often rested for a period after heavy tapping. Production commences when a tree is 5 or 6 years old and with proper management the tree’s useful life may extend up to 30 years. The trees can be cultivated at a density of 375 trees per hectare (150 trees per acre), approximately 2,500 kilograms of rubber can be produced per hectare per year (one ton per acre per year).
The truth is that they are not; not when you consider what it takes to harvest the raw material, to tap the sap from the Rubber Tree, and then to process this precious raw material into the best quality 100% natural latex mattress. The technique for tapping latex from rubber trees eliminates a need to cut down the tree for latex extraction, creating a sustainable relationship between sleep and sap. Latex is extracted by carefully cutting the bark of rubber trees (which heals rapidly) to allow the flow of the white milk-type sap without damaging the tree. Rubber trees can yield latex for as long as 30 years. When the trees are harvested, the land is replanted and the Rubber-wood is used to create furniture. Latex is all-natural, and biodegradable. In order to appreciate the value of latex, it is necessary to understand that each rubber tree harvest is about 15 grams of latex, daily. The core of a queen sized mattress requires the daily output of 2,500 trees that spread over 12 acres of rubber plantation. This provides a living to eight rubber tappers. Interestingly, these rubber trees account for the removal of 143 metric tons of Carbon Dioxide from the environment over one year.
The Dunlop processed latex is the original process which produces 100% natural latex. When we say that our latex mattresses are made from 100% natural latex it means that there are no synthetic polymers or fillers mixed with our natural latex polymer. However, it is always necessary to include 6% -7% of other natural and non- toxic materials to convert the 100% natural liquid latex polymer into the natural latex foam for the 100% natural latex mattresses.
More detailed information can be found in our ECO Institute test results.
Talalay latex mattresses have a synthetic blended latex mattress core. The percentage of synthetic material blended with the natural latex polymer can vary from 20% to 80% depending on the manufacturer. European manufacturers in particular favour the Talalay process as they need to compensate for the high import costs of getting the natural latex from Asian countries by adding petroleum based synthetic polymers.